LAW: A Novel Mechanism for Addressing Hidden Terminal Problem in LTE-U and Wi-Fi Networks

Abstract

Recently, the use of LTE in unlicensed spectrum (LTE-U) has gained a lot of attention. One of the daunting tasks before any such employment was to ensure the fair sharing of unlicensed spectrum between LTE-U and Wi-Fi radio access technologies (RATs), which now seems to be well addressed in the literature. However, along with fair sharing, the efficient utilization of unlicensed spectrum is also of profound significance, which pushes the need for coordination between LTE-U and Wi-Fi. Hence, this letter proposes a novel LTE-U and Wi-Fi (LAW) inter-RAT coordination mechanism for a more efficient utilization of the unlicensed spectrum. The aim is to address the inter-RAT hidden terminal problem between LTE-U and Wi-Fi and, thereby, offer better spectral efficiency. We modify the regular clear-to-send (CTS)-to-self frame and suggest the transmissions of modified CTS-to-self from LTE-U nodes to solve this hidden terminal issue. Further gains are extracted by allowing the simultaneous transmissions of LTE-U and Wi-Fi whenever possible.